Okay, so awhile back, like a month in real life, shadowmere got killed by like 4 giants. And i've read that she'll come back in like 3 days either where she died, or at the lake she came forth from. Well i've checked both and nothing. Any help?

I believe it is supposed to be 10 in game days, but then others have said 15 to 20 in game days - and yet others say a full 30 days (and stay out of that particular cell for that time period). Thereafter, Shadowmere is supposed to respawn at the lake from whence she came

Ouch. I'd heard 72 hours, too. I've reloaded my latest Save after the few time's I've killed him. ...probably stay out of the cell (WTFever that is - seems nebulous to me as to what exactly constitutes the "cell") like Psymer suggested.

yeah true, i've heard all of them. But i am waaaay past 30 days though....

Supposedly he comes back where he died.

I have had Shadowmere die twice. Both times it took 10 game days to return and both times it returned to the place of death, not the lake.

One of them was in the woods pretty deep and it took me a long time to find it. I was looking within ten feet and had its black coat was really hard to see.

Which reminds me... will the aura of living things shout work... or is it undead?

Ha. Did the same thing in losing him. Problem is, I cannot for the life of me remember where.

Fare-the-well freaky death-horse............

I don't have souls invested in Aura Whisper, but I cast Detect Life and he glowed blue if that's any indication.

Is this true with any horse? It respawns 10, 30 days or whatever after being killed?

I don't think so Trix. Just Shadowmere.

If you are on a PC, you could try using this mod - essentially you whistle, and the horse comes to you if it is in the same cell as you are. Can't give an opinion on its effectiveness though, since I have not used it, but it seems to have a fair number of endorsemants:

Horse Whistle: "Currently this mod is incredibly basic. All it does is attempt to find a reference to your last ridden horse, and tell the game to have it path to your current location. I'm not sure what happens when the horse is in an unloaded cell, but it works with horses in the same cell."

http://skyrim.nexusmods.com/downloads/file.php?id=1767

She died on one of my characters and I couldn't find her. After Two Weeks, I started doing Dark Brotherhood quests for the Night Mother and had to go to the Solitude Stables to kill someone.... Guess what? Shadowmere was there!